The following is a list of members of the United States Congress who have declared themselves to be socialists or have been a member of a socialist organization in the United States.

History From the 1890s to the 1910s, most socialists who won election to public office ran on the Populist or Socialist Party of America (SPA) ballot lines. While the SPA won a few federal elections, its electoral power was much greater in local and state elections, and briefly held over 1,000 local offices. During the First Red Scare, the House of Representatives twice refused to seat socialist Victor Berger, who would be convicted of violating the Espionage Act of 1917 and again won his seat.

Very few Communist Party USA (CPUSA) members have ever won federal office, and never as open Communists. The Second Red Scare and McCarthy era resulted in persecution of socialists, removal of socialists from unions, and weaker socialist electoral outcomes.

Starting in the 1980s, a small number of social-democratic and socialist Democrats affiliated with the Democratic Socialists of America (DSA) began to be elected. After the Bernie Sanders 2016 presidential campaign and explosion of DSA membership, the DSA rapidly gained half a dozen seats in the House. In 2021, there were more socialists in Congress than any point in US history, most of whom are members of the DSA. In 2024, after Cori Bush and Jamaal Bowman lost re-election and Greg Casar and Summer Lee lost their DSA endorsements, that number shrank again.

Members elected as socialists The table below lists members of the United States Congress who were open socialists or open members of a socialist organization during their time in office.

Member Photo Term start Term end Ballot line Note Current PA-12 Democratic Party Lee describes herself as a democratic socialist. She was a member of the Democratic Socialists of America from 2018 to 2021. Lee joined DSA in 2018, MO-1 Democratic Party Bush is a democratic socialist and a member of the Democratic Socialists of America. NY-16 Democratic Party Bowman is a democratic socialist and a member of the Democratic Socialists of America. Current NY-14 Democratic and Working Families (fusion) Ocasio-Cortez is a democratic socialist. She was a member of the Democratic Socialists of America from 2018 to 2019; she rejoined the group in August 2026. Current MI-12 Democratic Party Tlaib is a democratic socialist and a member of the Democratic Socialists of America. Current VT-Sen Independent Sanders is a democratic socialist. VT-AL Independent CA-9 Democratic Party Dellums was a democratic socialist. He was a founding member of the Democratic Socialist Organizing Committee before becoming vice-chair of the Democratic Socialists of America. MI-13 Democratic Party Conyers was a democratic socialist associated with the Democratic Socialist Organizing Committee. He was present at the founding of the Democratic Socialists of America in 1983. NY-24 American Labor Party Isacson was a socialist who worked alongside Vito Marcantonio. In April 1948, he was the first member of Congress to be denied a United States passport by the State Department, when he attempted to go to Paris to attend a conference for the American Council for a Democratic Greece, which opposed the Greek government in the Greek Civil War.Haig v. Agee, 453 U.S. 280 (1981), at 302 PR-AL Republican Union Pagán was a socialist and a member of the Socialist Party of Puerto Rico. He was appointed resident commissioner in a Socialist-Republican Union coalition. NY-18 American Labor Party Marcantonio was a socialist and a New Deal coalition member of the progressive branch of the Republican Party. In the 1940s and 1950s, he was surveilled by the FBI, who cited his affiliation with Communist-associated groups. NY-20 Republican Party PR-AL Socialist Party Iglesias was a socialist who co-founded the Socialist Party of Puerto Rico. WI-5 Socialist Party of AmericaBerger was a socialist, a founding member of the Social Democratic Party of America, and a founding member of its successor, the Socialist Party of America. In 1919, Berger was convicted of violating the Espionage Act of 1917 for publicizing his anti-interventionist views and was denied the seat to which he had been reelected in the House. In 1921, the criminal verdict was overturned by the Supreme Court in Berger v. United States. Berger was subsequently elected to three successive terms in the 1920s. WI-5 Socialist Party of America WI-5 Socialist Party of America NY-12 Socialist Party of AmericaLondon was a socialist and a founder of the Socialist Party of America. London voted against American entry into World War I and the Espionage Act of 1917 but voted for war funding bills. NY-12 Socialist Party of America NY-30 Democratic Party Lunn was a Christian socialist. In 1911, Lunn joined the Socialist Party of America and was elected mayor of Schenectady on the Socialist ticket, where he pursued a "sewer socialist" agenda. In 1916, Lunn was elected to the House as a Democrat. WI-4 Union Labor Party Smith was a socialist. He was elected to both the Milwaukee Common Council and the Wisconsin State Assembly on the Socialist ballot line. NY-6 Whig Greeley supported Fourierism in the 1840s, a utopian socialist tendency, and after 1848 shifted toward a form of liberal socialism or mutualism. IN-1 Democratic Party Owen supported Owenism, a utopian socialist tendency based on the ideas of his father, Robert Owen.

2026 House candidates running as socialists The following candidates have won Democratic Party primaries for the 2026 House elections in traditionally Democratic districts.

Member Photo Term start Term end Ballot line Note Current PA-3 Democratic Party Rabb is a democratic socialist and a member of the Democratic Socialists of America. Current NY-7 Democratic Party Valdez is a democratic socialist and a member of the Democratic Socialists of America. Current NY-10 Democratic and Working Families (fusion) Lander is a progressive and a democratic socialist. Lander was a member of the Democratic Socialists of America from 1987 to 2023, when he left the group citing the October 7 attacks. Current NY-13 Democratic Party Avila Chevalier is a democratic socialist and a member of the Democratic Socialists of America. Current CO-1 Democratic Party Kiros is a democratic socialist and a member of the Democratic Socialists of America. Current MI-13 Democratic Party McKinney is a democratic socialist and a member of the Democratic Socialists of America.

Members who were socialists out of office

The table below lists members of the United States Congress who were open socialists or open members of a socialist organization at some point in their life, but not while they held Congressional office. :

Member Photo Term start Term end Ballot line Note Current TX-35 Democratic Party Until mid-2022, Casar identified as a democratic socialist. He was a member of the Democratic Socialists of America from 2017 to 2022. CA-12 Democratic Party As a college student in 1968, Lee volunteered at the Oakland chapter of the Black Panther Party's Community Learning Center and worked on Black Panther co-founder Bobby Seale's 1973 campaign for mayor of Oakland. Lee was surveilled by the Federal Bureau of Investigation due to her Black Panther work. IL-1 Democratic Party He co-founded the Illinois chapter of the Black Panther Party in 1968, serving as the group's defense minister. He left the Black Panthers in 1974. VT-AL Democratic Party Meyer was a progressive. In 1970, he co-founded the Liberty Union Party, a socialist political party."L.U.P. History," The Official Website Of The Liberty Union Party – Vermont PA-6 Democratic Party Rhodes was a member of the Socialist Party of Pennsylvania. He was elected to the Socialist Party of America's National Executive Committee in 1936. WI-5 Democratic Party Biemiller was a member of the Socialist Party of America until 1935 before joining the Wisconsin Progressive Party, where he remained until 1944. He was later elected to the House as a Democrat. Ohm, Howard F.; Bryhan, Leone G., eds. The Wisconsin Blue Book, 1937 Madison: Democrat Printing Company, State Printer, 1937; pp. vii–viii, 53, 360, 432, 542, 543, 544, 551–552 WI-5 Democratic Party WA-1 Democratic Party From 1937 to 1939, De Lacy led the Seattle chapter of Communist Party USA. By the time he was elected to the House in 1944, De Lacy had moderated his political views and become "once more a loyal New Dealer". MN-3 Minnesota Farmer–Labor Party Teigan was a member of the Socialist Party of America from 1913 to 1916. He later joined the Nonpartisan League until 1923, when he became a member of the Minnesota Farmer–Labor Party.TEIGAN, Henry George MN-8 Minnesota Farmer–Labor Party Bernard was one of the few current, former, or future members of Congress to openly support the Spanish Republic in the Spanish Civil War. In the 1930s and 1940s, Bernard worked alongside Communist Party USA front groups. In 1952, Bernard was subpoenaed by the House Unamerican Activities Committee (HUAC), where he asserted his loyalty to America and took his Fifth Amendment privilege. In 1977, Bernard joined Communist Party USA. CA-12 Democratic Party Voorhis was inspired by Christian socialism and the Social Gospel tradition. He was a member of the Socialist Party of America until 1934, when he joined the Democratic Party. In 1936, Voorhis was elected as a "Progressive Roosevelt-Democrat". Voorhis was anti-communist and served on the House Un-American Activities Committee. WA-Sen Democratic Party Bone was a member of the Socialist Party of America until 1920; he later joined the Democratic Party. SD-AL People's Party In the 1900s, Knowles joined the Socialist Party of America. MN-7 People's Party In the 1900s, Boen joined the Socialist Party of America. MN-5 People's Party In the 1900s, Halvorson joined the Socialist Party of America.

Members with disputed ideologies

The table below includes members who have been described as socialist, but do not identify with the ideology.